The present invention relates to ship mooring systems, and particularly to such systems which include a mooring cable (sometimes called a hawser cable) securing the ship to a fixed object, such as an anchor or a dock.
Moored ships commonly exhibit oscillatory behaviour, referred to as "fishtailing" or "kiting". Such behaviour results in very large tension forces being produced on the mooring cable as it restrains the ship at the ends of its swings. In many moorings, particularly shallow water moorings, this is a serious problem because the mooring system does not have sufficient capacity to absorb the tension surges. Failure of either the mooring system or the ship bow structure is not uncommon in these cases. If the mooring system fails, this could result in the loss of the ship and its contents, and also could cause considerable environmental damage. On the other hand, if the mooring system is too rigid to prevent the oscillatory movements of the ship, failure could occur at the bow of the ship. The latter possibility is particularly increasing because of recent trends to trade-off structural strength of ships in order to maximize the cargo-carrying capability of commercial ships, or the armament/weapons-carrying capability of combatant ships.